JP2018059076A - Method for producing fluorine-containing polymer having crosslinkable group, method for producing curable composition, fluorine-containing polymer having crosslinkable group and curable composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a fluorine-containing polymer having a crosslinkable group excellent in crosslinkability and solubility without impairing each of characteristics as the fluorine-containing polymer; a fluorine-containing polymer having a crosslinkable group; a method for producing a curable composition containing the fluorine-containing polymer; and a curable composition.SOLUTION: A method for producing a fluorine-containing polymer includes: polymerizing a monomer component containing a monomer having a fluorine atom and an iodine atom and a monomer having a fluorine atom and no iodine atom to obtain a precursor polymer having either or both of a group (g1) and a group (g2); and converting the iodine atom in the precursor polymer into a group having a crosslinkable group to obtain a fluorine-containing polymer having a crosslinkable group.SELECTED DRAWING: None

Description

  The present invention relates to a method for producing a fluorinated polymer having a crosslinkable group, a method for producing a curable composition containing a fluorinated polymer having a crosslinkable group, a fluorinated polymer having a crosslinkable group, and a fluorinated polymer having a crosslinkable group. The present invention relates to a curable composition containing a fluoropolymer.

  A cured product comprising a curable composition containing a fluorine-containing polymer has a low dielectric constant, a low refractive index, and excellent transparency, water / oil repellency, heat resistance, light resistance, chemical stability, gas permeability, and the like. Therefore, it is used for electronic members (printed circuit boards, etc.), optical members (optical waveguides, lenses, antireflection films, etc.), water / oil repellency imparting agents, mold release agents, biochips, and the like.

  In order to improve the curability of a curable composition containing a fluoropolymer, a crosslinkable group is introduced into the fluoropolymer to improve the crosslinkability of the fluoropolymer. As a method for introducing a crosslinkable group into the fluorine-containing polymer, for example, a method of polymerizing a monomer having a fluorine atom and a monomer having a crosslinkable group, or a monomer having a fluorine atom and a crosslinkable group can be introduced. Examples thereof include a method of polymerizing a monomer having a group and then introducing a crosslinkable group into the group.

  However, when a crosslinkable group is introduced into the fluoropolymer by the above method, the proportion of units having a crosslinkable group as a pendant group increases, that is, the proportion of units based on a monomer having a fluorine atom decreases. The above characteristics may be impaired.

In Patent Document 1, after replacing the -COOH derived from the polymerization initiator at the end of the fluoropolymer having an aliphatic ring structure in -COOCH _3, the -COOCH ₃ amine group-containing silane coupling agent amino A group in which a trimethoxysilyl group is introduced into the terminal of a fluorine-containing polymer having an aliphatic ring structure by reacting the group is described.

JP-A-4-226177

  However, the fluorine-containing polymer having an aliphatic ring structure described in Patent Document 1 is composed of a linear molecular chain having a high molecular weight, and at most two trimethoxysilyl groups can be introduced per molecular chain. . Therefore, the fluorine-containing polymer described in Patent Document 1 has poor crosslinkability and is insufficient in solubility in a solvent. When used as a solution, a solvent having a very high fluorine content such as a perfluoro compound is used. There is a need.

  The present invention provides a method for producing a fluoropolymer having a crosslinkable group that does not impair each characteristic as a fluoropolymer and has excellent crosslinkability and solubility, a fluoropolymer having a crosslinkable group, and a fluoropolymer as a fluoropolymer. Disclosed are a method for producing a curable composition and a curable composition, which do not impair each property and are excellent in curability and compatibility of each component.

ただし、Ｒ^１は、エーテル結合性酸素原子を有してもよい１価のペルフルオロ有機基またはフッ素原子であり、Ｒ^２およびＲ^３は、それぞれ独立に、フッ素原子、炭素数１〜５のペルフルオロアルキル基または炭素数１〜５のペルフルオロアルコキシ基であり、Ｒ^４は、５員環の一部または６員環の一部を構成する、エーテル結合性酸素原子を有してもよい直鎖状または分岐状のペルフルオロアルキレン基である。
＜２＞前記フッ素原子を有し、ヨウ素原子を有さないモノマーが、脂肪族環構造を有するモノマー、および環化重合によって脂肪族環構造を形成し得るモノマーのいずれか一方または両方を含む、前記＜１＞の架橋性基を有する含フッ素ポリマーの製造方法。
＜３＞前記前駆ポリマーおよび前記架橋性基を有する含フッ素ポリマーが、分岐分子鎖からなる、前記＜１＞または＜２＞の架橋性基を有する含フッ素ポリマーの製造方法。
＜４＞前記架橋性基が、下式（ｇ３）で表される基、エポキシ基、ビニル基および下式（ｇ４）で表される基からなる群から選ばれる少なくとも１種である、前記＜１＞〜＜３＞のいずれかの架橋性基を有する含フッ素ポリマーの製造方法。
−ＯＣＯＣＸ^１＝ＣＨ_２ （ｇ３）
−ＳｉＸ^２ _ｎ（ＯＲ^５）_３−ｎ （ｇ４）
ただし、Ｘ^１は、水素原子、フッ素原子、塩素原子、炭素数１〜４のアルキル基または炭素数１〜４のペルフルオロアルキル基であり、Ｘ^２は、炭素数１〜４のアルキル基であり、ｎは、０〜２の整数であり、Ｒ^５は、炭素数１〜４のアルキル基である。
＜５＞前記架橋性基を有する含フッ素ポリマーの質量平均分子量が、５，０００〜８０，０００である、前記＜１＞〜＜４＞のいずれかの架橋性基を有する含フッ素ポリマーの製造方法。
＜６＞前記＜１＞〜＜５＞のいずれかの架橋性基を有する含フッ素ポリマーの製造方法によって架橋性基を有する含フッ素ポリマーを得て、該含フッ素ポリマーを含む硬化性組成物を調製する、硬化性組成物の製造方法。
＜７＞フッ素原子を有する単位を有する分岐分子鎖からなり、前記分岐分子鎖の複数の末端に架橋性基を有する、架橋性基を有する含フッ素ポリマー。
＜８＞前記フッ素原子を有する単位の少なくとも一部が、フッ素原子を有し、かつ脂肪族環構造を有する単位である、前記＜７＞の架橋性基を有する含フッ素ポリマー。
＜９＞下式（ｇ１１）で表される基および下式（ｇ１２）で表される基のいずれか一方または両方を有する、前記＜７＞または＜８＞の架橋性基を有する含フッ素ポリマー。

ただし、Ｒ^１は、エーテル結合性酸素原子を有してもよい１価のペルフルオロ有機基またはフッ素原子であり、Ｒ^２およびＲ^３は、それぞれ独立に、フッ素原子、炭素数１〜５のペルフルオロアルキル基または炭素数１〜５のペルフルオロアルコキシ基であり、Ｒ^４は、５員環の一部または６員環の一部を構成する、エーテル結合性酸素原子を有してもよい直鎖状または分岐状のペルフルオロアルキレン基であり、Ａは、架橋性基を有する基である。
＜１０＞前記架橋性基が、下式（ｇ３）で表される基、エポキシ基、ビニル基および下式（ｇ４）で表される基からなる群から選ばれる少なくとも１種である、前記＜７＞〜＜９＞のいずれかの架橋性基を有する含フッ素ポリマー。
−ＯＣＯＣＸ^１＝ＣＨ_２ （ｇ３）
−ＳｉＸ^２ _ｎ（ＯＲ^５）_３−ｎ （ｇ４）
ただし、Ｘ^１は、水素原子、フッ素原子、塩素原子、炭素数１〜４のアルキル基または炭素数１〜４のペルフルオロアルキル基であり、Ｘ^２は、炭素数１〜４のアルキル基であり、ｎは、０〜２の整数であり、Ｒ^５は、炭素数１〜４のアルキル基である。
＜１１＞質量平均分子量が、５，０００〜８０，０００である、前記＜７＞〜＜１０＞のいずれかの架橋性基を有する含フッ素ポリマー。
＜１２＞前記＜７＞〜＜１１＞のいずれかの架橋性基を有する含フッ素ポリマーを含む、硬化性組成物。 The present invention has the following aspects.
<1> A monomer component containing a monomer having a fluorine atom and an iodine atom and a monomer having a fluorine atom and no iodine atom is polymerized to obtain a group represented by the following formula (g1) and the following formula ( g2) is a fluorine-containing polymer having a crosslinkable group obtained by obtaining a precursor polymer having one or both of the groups represented by g2) and converting the iodine atom in the following formula in the precursor polymer to a group having a crosslinkable group Manufacturing method.

However, R ¹ is a monovalent perfluoro organic group or a fluorine atom which may have an etheric oxygen atom, and R ² and R ³ are each independently a fluorine atom, a C 1-5 perfluoro An alkyl group or a perfluoroalkoxy group having 1 to 5 carbon atoms, and R ⁴ is a straight chain which may have a part of a 5-membered ring or a part of a 6-membered ring and may have an etheric oxygen atom Or it is a branched perfluoroalkylene group.
<2> The monomer having a fluorine atom and having no iodine atom includes one or both of a monomer having an aliphatic ring structure and a monomer capable of forming an aliphatic ring structure by cyclopolymerization. The manufacturing method of the fluorine-containing polymer which has a crosslinkable group of said <1>.
<3> The method for producing a fluorinated polymer having the <1> or <2> crosslinkable group, wherein the precursor polymer and the fluorinated polymer having a crosslinkable group are composed of branched molecular chains.
<4> The crosslinkable group is at least one selected from the group consisting of a group represented by the following formula (g3), an epoxy group, a vinyl group, and a group represented by the following formula (g4), A method for producing a fluoropolymer having a crosslinkable group according to any one of 1> to <3>.
-OCOCX ¹ = _CH 2 (g3)
-SiX ² _n (OR ⁵ ) _3-n (g4)
However, ^{X 1} is a hydrogen atom, a fluorine atom, a chlorine atom, a perfluoroalkyl group having 1 to 4 alkyl groups or carbon atoms having 1 to 4 carbon atoms, ^{X 2} is an alkyl group having 1 to 4 carbon atoms , N is an integer of 0 to 2, and R ⁵ is an alkyl group having 1 to 4 carbon atoms.
<5> Production of fluorinated polymer having a crosslinkable group according to any one of <1> to <4>, wherein the fluorinated polymer having a crosslinkable group has a mass average molecular weight of 5,000 to 80,000. Method.
<6> Obtaining a fluorinated polymer having a crosslinkable group by a method for producing a fluorinated polymer having a crosslinkable group according to any one of <1> to <5>, and providing a curable composition containing the fluorinated polymer. A method for producing a curable composition to be prepared.
<7> A fluorine-containing polymer having a crosslinkable group, comprising a branched molecular chain having a unit having a fluorine atom, and having a crosslinkable group at a plurality of terminals of the branched molecular chain.
<8> The fluorine-containing polymer having a crosslinkable group according to <7>, wherein at least a part of the unit having a fluorine atom is a unit having a fluorine atom and an aliphatic ring structure.
<9> The fluorine-containing polymer having the crosslinkable group of <7> or <8>, which has one or both of the group represented by the following formula (g11) and the group represented by the following formula (g12) .

However, R ¹ is a monovalent perfluoro organic group or a fluorine atom which may have an etheric oxygen atom, and R ² and R ³ are each independently a fluorine atom, a C 1-5 perfluoro An alkyl group or a perfluoroalkoxy group having 1 to 5 carbon atoms, and R ⁴ is a straight chain which may have a part of a 5-membered ring or a part of a 6-membered ring and may have an etheric oxygen atom Or it is a branched perfluoroalkylene group, and A is a group having a crosslinkable group.
<10> The crosslinkable group is at least one selected from the group consisting of a group represented by the following formula (g3), an epoxy group, a vinyl group, and a group represented by the following formula (g4), 7> to <9> A fluorine-containing polymer having a crosslinkable group.
-OCOCX ¹ = _CH 2 (g3)
-SiX ² _n (OR ⁵ ) _3-n (g4)
However, ^{X 1} is a hydrogen atom, a fluorine atom, a chlorine atom, a perfluoroalkyl group having 1 to 4 alkyl groups or carbon atoms having 1 to 4 carbon atoms, ^{X 2} is an alkyl group having 1 to 4 carbon atoms , N is an integer of 0 to 2, and R ⁵ is an alkyl group having 1 to 4 carbon atoms.
<11> A fluorine-containing polymer having a crosslinkable group according to any one of <7> to <10>, wherein the mass average molecular weight is 5,000 to 80,000.
<12> A curable composition comprising a fluorine-containing polymer having a crosslinkable group according to any one of <7> to <11>.

According to the method for producing a fluorinated polymer having a crosslinkable group of the present invention, it is possible to produce a fluorinated polymer having a crosslinkable group excellent in crosslinkability and solubility without impairing the properties of the fluorinated polymer.
According to the method for producing a curable composition of the present invention, it is possible to produce a curable composition that does not impair each characteristic as a fluoropolymer and is excellent in curability and compatibility of each component.
The fluoropolymer having a crosslinkable group of the present invention does not impair each characteristic as a fluoropolymer, and is excellent in crosslinkability and solubility.
The curable composition of the present invention does not impair each characteristic as a fluorine-containing polymer, and is excellent in curability and compatibility of each component.

  The monomer represented by the formula (m1) is referred to as a monomer (m1). A group represented by the formula (g1) is referred to as a group (g1). The polymer represented by the formula (p1) is referred to as a polymer (p1). The same applies to monomers, groups and polymers represented by other formulas.

The following expressions and definitions of terms apply throughout this specification and the claims, unless otherwise specified.
The “unit” means an atomic group based on the monomer formed by radical polymerization of the monomer. The unit may be an atomic group directly formed by a polymerization reaction, or may be an atomic group in which a part of the atomic group is converted into another structure by treating the polymer.
A “monomer” is a compound having a polymerization-reactive carbon-carbon double bond.
“Fluorine-containing polymer” means a polymer having a fluorine atom bonded to a carbon atom.
“Perfluoropolymer” means a polymer in which the ratio of the number of carbon-fluorine bonds to the sum of the number of carbon-halogen bonds and the number of carbon-hydrogen bonds in the polymer is 95% or more. The ratio of the number of carbon-fluorine bonds to the sum of the number of carbon-halogen bonds and the number of carbon-hydrogen bonds in the polymer can be calculated using, for example, the measurement result of elemental analysis.
The “iodine-containing perfluoropolymer” means a polymer in which a part of fluorine atoms of the perfluoropolymer is replaced with iodine atoms.
“Perfluoromonomer” means a monomer in which all of hydrogen atoms bonded to carbon atoms are replaced with fluorine atoms.
The “iodine-containing perfluoromonomer” means a monomer in which part of the fluorine atom of the perfluoromonomer is replaced with an iodine atom.
The “perfluoroalkyl group” means a group in which all of the hydrogen atoms of the alkyl group are replaced with fluorine atoms.
The “perfluoroalkylene group” means a group in which all of the hydrogen atoms of the alkylene group are replaced with fluorine atoms.
The “branched molecular chain” means a molecular chain composed of branched units having at least one branch point. A molecular chain composed of linearly linked units and having a pendant group (a side branch that is not a side chain composed of a plurality of units) is not a branched molecular chain.
“˜” indicating a numerical range means that numerical values described before and after the numerical value range are included as a lower limit value and an upper limit value.

<Method for producing fluorine-containing polymer having a crosslinkable group>
The method for producing a fluorine-containing polymer having a crosslinkable group according to the present invention obtains a specific precursor polymer having an iodine atom, converts the iodine atom of the precursor polymer into a group having a crosslinkable group, This is a method for obtaining a fluorine-containing polymer (hereinafter also referred to as a fluorine-containing polymer (A1)).

(Precursor polymer)
The precursor polymer includes a monomer having a fluorine atom and an iodine atom (hereinafter also referred to as monomer (m1)) and a monomer having a fluorine atom and not having an iodine atom (hereinafter also referred to as monomer (m2)). It is obtained by polymerizing a monomer component containing

As the monomer (m1), an iodine-containing perfluoromonomer is preferable since the fluorine-containing polymer (A1) can be increased in the fluorine-containing polymer (A1), and a fluorine-containing polymer (A1) having excellent properties as the fluorine-containing polymer can be obtained.
The monomer (m1) is preferably a monomer having a group (g1) described later from the viewpoint of easily converting the iodine atom of the precursor polymer into a group having a crosslinkable group, and is opposite to the polymerization-reactive carbon-carbon double bond. The monomer which has group (g1) mentioned later at the terminal of the side is more preferable. By using the above monomer, a fluorine-containing polymer having a molecular branched chain can be obtained.

Examples of the monomer (m1) include the following monomers.
_{CF 2 = CFOCF 2 CF (CF} 3) OCF 2 CF 2 -I,
_{CF 2 = CFOCF 2 CF (CF} 3) OCF 2 CF (CF 3) OCF 2 CF 2 -I,
_{CF 2 = CFO (CF 2)} 2 -I,
_{CF 2 = CFO (CF 2)} 3 -I,
_{CF 2 = CFO (CF 2)} 4 -I,
_{CF 2 = CFO (CF 2)} 5 -I,
_{CF 2 = CFO (CF 2)} 6 -I,
_{CF 2 = CFO (CF 2)} 8 -I,
_{CF 2 = CFOCF 2 CF (CF} 3) -I,
_{CF 2 = CFOCF 2 CF (CF} 3) OCF 2 CF (CF 3) -I,
_{CF 2 = CFO (CF 2)} 3 OCF 2 CF 2 -I,
_{CF 2 = CFOCF 2 CF 2 OCF} 2 CF 2 CF 2 CF 2 -I,
_{CF 2 = CFOCF (CF 3)} CF 2 OCF 2 CF 2 -I,
_{CF 2 = CFOCF 2 CF 2 CH} 2 -I,
_{CF 2 = CFOCF 2 CF (CF} 3) OCF 2 CF 2 CH 2 -I,
_{CF 2 = CFOCF 2 CF 2 CH} 2 CH 2 CH 2 -I,
_{CH 2 = CHCF 2 CF 2 -I} ,
_{CH 2 = CHCF 2 CF 2 CF} 2 CF 2 -I,
_{CH 2 = CFCF 2 CF 2 -I} ,
_{CH 2 = CFCF 2 CF 2 CF} 2 CF 2 -I,
_{CH 2 = CFCF 2 OCF (CF} 3) -I,
_{CH 2 = CFCF 2 OCF (CF} 3) CF 2 OCF (CF 3) -I,
_{CH 2 = CFCF 2 OCF (CF} 3) CF 2 OCF (CF 3) CF 2 OCF (CF 3) -I.

The monomer (m1) can be synthesized, for example, by the method described in the examples. The monomer (m1) is preferably an iodine-containing perfluoromonomer. Since the iodine-containing perfluoromonomer can be easily synthesized from a general-purpose perfluoromonomer having a —SO ₂ F group, the precursor polymer and the fluorine-containing polymer (A1) can be produced at low cost.

As the monomer (m2), a perfluoromonomer is preferable because the ratio of fluorine atoms in the fluoropolymer (A1) can be increased and a fluoropolymer (A1) having excellent properties as the fluoropolymer can be obtained.
As the monomer (m2), the group (g1) or group (to be described later) when the iodine atom is bonded to the unit based on the monomer (m2) from the viewpoint of easily converting the iodine atom of the precursor polymer into a group having a crosslinkable group. A monomer that can be a unit having g2) is preferable, and a monomer (m20) and a monomer (m23), which will be described later, are more preferable because they provide a fluorine-containing polymer (A1) having good solubility in a solvent. When the monomer (m20) or the monomer (m23) is contained as a polymerization unit, the resulting polymer tends to be amorphous. An amorphous polymer tends to be more soluble in a solvent than a crystalline polymer.

As the monomer (m2), for example, a monomer having an aliphatic ring structure, a monomer capable of forming an aliphatic ring structure by cyclopolymerization, tetrafluoroethylene, chlorotrifluoroethylene, trifluoroethylene, vinylidene fluoride, fluoride Vinyl, hexafluoropropylene, (perfluoroalkyl) ethylene (eg, (perfluorobutyl) ethylene), (perfluoroalkyl) propene (eg, 3-perfluorooctyl-1-propene), a fluorine atom, and precursor of an ion exchange group And monomers having a body group.
The ion-exchange _{^{groups, -SO 3 - Z +, -COO}} - Z + (. However, ^{Z +} is, ^{H +,} a monovalent metal cation, an ammonium ion, etc.) and the like. Examples of the precursor group include —SO ₂ F, —COOR (R is an alkyl group, etc.) and the like.

  As the monomer (m2), a fluorine-containing polymer (A1) having excellent solubility in a solvent and excellent properties can be obtained, so that a monomer having an aliphatic ring structure and an aliphatic ring structure are formed by cyclopolymerization. Those containing either or both of the possible monomers are preferred.

The aliphatic ring structure may have one or two ether-bonded oxygen atoms, and is a cyclic organic group in which some or all of the hydrogen atoms bonded to the carbon atoms are substituted with fluorine atoms.
The polymerization-reactive carbon-carbon double bond in the monomer having an aliphatic ring structure may be composed of two adjacent carbon atoms constituting the aliphatic ring structure. And one carbon atom existing outside the aliphatic ring structure adjacent thereto.

Examples of the monomer having an aliphatic ring structure include a monomer (m20) and a monomer (m22) described later, and the monomer (m20) is preferable because it can be a unit having a group (g2) described later.
The monomer (m20) is represented by the following formula.

R ^{2, R 3} and ^{R 4} are the same as ^R 2, ^{R 3} and ^{R 4} in later-described group (g2).
As the monomer (m20), the monomer (m21) is preferable from the viewpoint of polymerization reactivity and ease of synthesis.

R ¹¹ and R ¹² are each independently a fluorine atom or a C 1-5 perfluoroalkyl group.
R ¹³ and R ¹⁴ are each independently a fluorine atom, a C 1-5 perfluoroalkyl group, or a C 1-5 perfluoroalkoxy group. From the viewpoint of high polymerization reactivity of the monomer (m21), at least one of R ¹³ and R ¹⁴ is preferably a fluorine atom, and more preferably both are fluorine atoms.
The perfluoroalkyl group and the perfluoroalkoxy group may be linear or branched, and preferably linear.

  Examples of the monomer (m21) include monomers (m21-1) to (m21-7).

  The monomer (m22) is represented by the following formula.

R ^{21 to} R ²⁶ are each independently a monovalent perfluoro organic group which may have an etheric oxygen atom or a fluorine atom. As the monovalent perfluoro organic group, a perfluoroalkyl group is preferable. When the perfluoroalkyl group has an etheric oxygen atom, the oxygen atom may be one or two or more. Further, the oxygen atom may be inserted between the carbon-carbon bonds of the perfluoroalkyl group, or may be present at the terminal on the side bonded to the carbon atom constituting the ring of the monomer (m22). The perfluoroalkyl group may be linear or branched, and is preferably linear.
In view of the high polymerization reactivity of the monomer (m22), at least one of R ²⁵ and R ²⁶ is preferably a fluorine atom, and more preferably both are fluorine atoms.

  Examples of the monomer (m22) include the monomer (m22-1) and the monomer (m22-2), and the monomer (m22-1) is preferable from the viewpoint of easy synthesis.

A monomer (m23) is mentioned as a monomer which can form an aliphatic ring structure by the said cyclopolymerization.
The monomer (m23) is represented by the following formula.
^{CF (R 31) = C (} R 33) -O-CF (R 36) -CF (R 35) -C (R 34) = CF (R 32) (m23)
R ^{31 to} R ³⁶ are each independently a monovalent perfluoro organic group which may have an etheric oxygen atom or a fluorine atom. As the monovalent perfluoro organic group, a perfluoroalkyl group is preferable. When the perfluoroalkyl group has an etheric oxygen atom, the oxygen atom may be one or two or more. Further, the oxygen atom may be inserted between the carbon-carbon bonds of the perfluoroalkyl group, or may exist so as to be directly bonded to the carbon atom to which the perfluoroalkyl group is bonded. The perfluoroalkyl group may be linear or branched, and is preferably linear.
R ^{31 to} R ³⁴ are more preferably a fluorine atom from the viewpoint of high polymerization reactivity of the monomer (m23).

Examples of the monomer (m23) include monomers (m23-1) to (m23-3), and the monomer (m23-1) is preferable from the viewpoint of easy synthesis.
_{CF 2 = CF-O-CF} 2 -CF 2 -CF = CF 2 (m23-1)
_{CF 2 = CF-O-CF} 2 -CF (CF 3) -CF = CF 2 (m23-2)
_{CF 2 = CF-O-CF} (CF 3) -CF 2 -CF = CF 2 (m23-3)

The monomer (m1) and the monomer (m2) are appropriately selected so that the precursor polymer has one or both of a group (g1) and a group (g2) described later.
The monomer component may contain a third monomer other than the monomer (m1) and the monomer (m2) as necessary, as long as the effects of the present invention are not impaired.
Examples of the third monomer include ethylene, propylene, cyclopentene, norbornene, and the like.

  The charged molar ratio of the monomer (m1) and the monomer (m2) is such that the molar ratio (m2 / m1) of the unit based on the monomer (m2) to the unit based on the monomer (m1) and the molecular weight in the precursor polymer described later are preferable. It adjusts suitably so that it may become.

Examples of the polymerization method include known polymerization methods such as solution polymerization, suspension polymerization, emulsion polymerization, and bulk polymerization.
Polymerization is performed under conditions where radicals occur. Examples of the method for generating radicals include a method of adding a radical initiator, a method of irradiating radiation such as ultraviolet rays, γ rays, and electron beams.

  Examples of the radical initiator include bis (fluoroacyl) peroxide, bis (chlorofluoroacyl) peroxide, dialkyl peroxydicarbonate, diacyl peroxide, peroxyester, azo compound, and persulfate.

Solvents used in the solution polymerization method include perfluorotrialkylamine (perfluorotributylamine, etc.), perfluorocarbon (perfluorohexane, perfluorooctane, etc.), hydrofluorocarbon (1H, 4H-perfluorobutane, 1H-perfluorohexane, etc.), hydro Chlorofluorocarbon (3,3-dichloro-1,1,1,2,2-pentafluoropropane, 1,3-dichloro-1,1,2,2,3-pentafluoropropane, etc.), hydrofluoroether (CF ₃ CH ₂ OCF ₂ CF ₂ H, etc.).

  In the solution polymerization method, a monomer component, a radical initiator, and the like are added to a solvent, and radicals are generated in the solvent to polymerize the monomer component. The addition of the monomer component and the radical initiator may be batch addition, sequential addition, or continuous addition.

  The precursor polymer obtained by polymerizing the monomer component containing the monomer (m1) and the monomer (m2) has one or both of the group (g1) and the group (g2).

R ¹ is a monovalent perfluoro organic group which may have an etheric oxygen atom or a fluorine atom. As the monovalent perfluoro organic group, a perfluoroalkyl group is preferable. When the perfluoroalkyl group has an etheric oxygen atom, the oxygen atom may be one or two or more. The oxygen atom may be inserted between the carbon-carbon bonds of the perfluoroalkyl group, or may be present at the terminal of the group (g1) on the side bonded to the carbon atom. The perfluoroalkyl group may be linear or branched, and is preferably linear. 1-6 are preferable and, as for carbon number of a perfluoroalkyl group, 1-4 are more preferable. R ¹ is preferably a fluorine atom, a trifluoromethyl group, or a pentafluoroethyl group, more preferably a fluorine atom or a trifluoromethyl group, and even more preferably a fluorine atom.

R ² and R ³ are each independently a fluorine atom, a C 1-5 perfluoroalkyl group or a C 1-5 perfluoroalkoxy group.
R ⁴ is a linear or branched perfluoroalkylene group that may have an ether-bonded oxygen atom, constituting a part of a 5-membered ring or a part of a 6-membered ring. When the perfluoroalkylene group has an etheric oxygen atom, the oxygen atom may be one or two. The oxygen atom may be inserted between the carbon-carbon bonds of the perfluoroalkylene group or may be present at the terminal.

Examples of the unit having the group (g1) include a unit based on the monomer (m1) from which the iodine atom is not removed; a unit based on the monomer (m2) (for example, the monomer (m23)) located at the end of the molecular chain And a unit having an iodine atom bonded thereto.
Examples of the unit having the group (g2) include a unit in which an iodine atom is bonded to a unit based on the monomer (m2) (for example, the monomer (m20)) located at the end of the molecular chain.
The iodine atom bonded to the unit based on the monomer (m2) is an iodine atom released from the unit based on the monomer (m1) during the polymerization of the monomer component, or an iodine atom that has moved from the monomer (m1) in the polymerization reaction system It is.

The molar ratio (m2 / m1) of the unit based on the monomer (m2) to the unit based on the monomer (m1) in the precursor polymer is preferably 3/1 to 100/1, and more preferably 5/1 to 50/1. If m2 / m1 is not less than the lower limit of the above range, a fluoropolymer (A1) excellent in each characteristic can be easily obtained. In addition, a sufficiently high molecular weight is easily obtained during polymerization. When m2 / m1 is not more than the upper limit of the above range, sufficient crosslinking reactivity is easily obtained in the fluoropolymer (A1). Moreover, the solubility to the solvent of a fluorine-containing polymer (A1) is easy to be acquired by the group which has a crosslinkable group.
The unit based on the monomer (m1) includes a unit (branch point) obtained by removing iodine atoms from the unit based on the monomer (m1). Further, the unit based on the monomer (m2) includes those in which an iodine atom is bonded to the unit based on the monomer (m2).

  The number of iodine atoms per polymer molecule in the precursor polymer may be appropriately adjusted according to the balance between the crosslinkability of the fluoropolymer (A1) and each characteristic as the fluoropolymer. If the number of iodine atoms per molecule of the polymer is large, the number of crosslinkable groups in the fluoropolymer (A1) is sufficiently increased, and the crosslinkability of the fluoropolymer (A1) is further improved. If the number of iodine atoms per molecule of the polymer is not too large, the number of crosslinkable groups in the fluoropolymer (A1) will not be excessive, and it will be difficult to impair each characteristic as the fluoropolymer.

As the precursor polymer, an iodine-containing perfluoropolymer is preferable from the viewpoint of obtaining a fluorine-containing polymer (A1) having excellent properties as a fluorine-containing polymer.
As the precursor polymer, a polymer having a branched molecular chain is preferred from the viewpoint that the number of crosslinkable groups introduced at the end of the molecular chain is increased and a fluoropolymer (A1) having excellent crosslinkability and solubility can be obtained.

  When the precursor polymer is composed of a branched molecular chain, the branch point of the branched molecular chain is composed of a unit obtained by removing iodine atoms from a unit based on the monomer (m1). The unit based on the monomer (m1) from which iodine atoms are extracted by radicals in the polymerization reaction system during the polymerization of the monomer component becomes the polymerization starting point, that is, the polymer branching point.

It can be confirmed by NMR measurement that the precursor polymer is a branched molecular chain by the presence of a peak derived from a unit based on the monomer (m1) and a peak derived from a unit based on the monomer (m2).
When the unit based on the monomer (m1) is a unit based on 8IVE described later, a peak derived from a fluorine atom bonded to a carbon atom bonded with an iodine atom in the vicinity of −60 to −65 ppm can be confirmed.
When the unit based on the monomer (m2) is a unit based on the monomer (m20), a peak derived from a fluorine atom bonded to a carbon atom of an aliphatic ring structure to which an iodine atom is bonded can be confirmed. For example, the monomer (m21- When the unit is based on 1), the above peak can be confirmed at around -45 ppm.
When the unit based on the monomer (m2) is a unit based on the monomer (m23), a peak derived from a fluorine atom bonded to a carbon atom bonded to an iodine atom can be confirmed. For example, a unit based on the monomer (m23-1) In this case, the peak can be confirmed in the vicinity of −45 to −50 ppm.
In addition, the value of chemical shift is a value when the chemical shift of the solvent perfluorobenzene is set to -162.7 ppm.

  The mass average molecular weight of the precursor polymer is preferably 5,000 to 80,000, more preferably 10,000 to 60,000, and further preferably 15,000 to 40,000. When the mass average molecular weight of the precursor polymer is within the above range, it is easy to obtain a fluorinated polymer (A1) having a mass average molecular weight in a preferred range described later. In addition, the mass mean molecular weight of this specification is a polymethyl methacrylate (henceforth PMMA) conversion mass mean molecular weight obtained by measuring with the below-mentioned method. The absolute molecular weight measured by a known method such as a light scattering method in a polymer having a branched structure is larger than the PMMA equivalent molecular weight.

(Fluoropolymer (A1))
The fluorine-containing polymer (A1) is obtained by converting the iodine atom of the precursor polymer into a group having a crosslinkable group.
The fluorine-containing polymer (A1) is preferably one in which all of the iodine atoms of the precursor polymer react to contain no iodine atom, and one having a high conversion rate of the iodine atom to a group having a crosslinkable group is preferred. . If iodine atoms remain in the fluorine-containing polymer (A1), the fluorine-containing polymer (A1) is easily deteriorated and colored by iodine released by light or heat.

  The fluoropolymer (A1) has one or both of the group (g11) and the group (g12).

R ^{1, R} 2, ^{R 3} and ^{R 4} are the same as ^{R 1,} R 2, ^{R 3} and ^{R 4} in the above-mentioned group (g1) and a group (g2).
A is a group having a crosslinkable group.

The group (g11) is obtained by converting the iodine atom of the group (g1) described above into a group having a crosslinkable group.
The group (g12) is obtained by converting the iodine atom of the group (g2) described above into a group having a crosslinkable group.

  Examples of the crosslinkable group include group (g3), epoxy group, vinyl group, group (g4), cyano group, maleimide group, azide group, ethynyl group, carboxy group, alkoxycarbonyl group, amino group, hydroxyl group, and the like. From the viewpoint of excellent crosslinkability of the fluoropolymer (A1), at least one selected from the group consisting of a group (g3), an epoxy group, a vinyl group and a group (g4) is preferable, and the group (g3), the epoxy group and the group At least one selected from the group consisting of (g4) is more preferable. In the present specification, terminal groups composed of iodine atoms and bromine atoms are excluded from the crosslinkable groups.

-OCOCX ¹ = _CH 2 (g3)
-SiX ² _n (OR ⁵ ) _3-n (g4)
However, ^{X 1} is a hydrogen atom, a fluorine atom, a chlorine atom, a perfluoroalkyl group having 1 to 4 alkyl groups or carbon atoms having 1 to 4 carbon atoms, ^{X 2} is an alkyl group having 1 to 4 carbon atoms , N is an integer of 0 to 2, and R ⁵ is an alkyl group having 1 to 4 carbon atoms.

Conversion of the iodine atom of the precursor polymer to a crosslinkable group can be carried out in the same manner as a known reaction in a low molecular weight compound.
As a method for converting the iodine atom of the precursor polymer into a group having a group (g3), for example, by the method described in US Pat. No. 4,058,573, the precursor polymer (hereinafter also referred to as polymer (p0)) is polymerized. (P1) and a polymer (p2) was obtained by the method described in JP-A-48-103504, and JP-A-53-139893, US Pat. No. 3,282,905 or JP-A-5-345732. The method of obtaining a polymer (p3) by the method of gazette publication is mentioned.
In addition, the polymer (p4) was obtained from the polymer (p0) by the method described in JP-B No. 46-25361, and Journal of Fluorine Chemistry, 1994, Vol. 68, No. 1, p. Examples include a method of obtaining a polymer (p6) in the same manner as the method of obtaining the polymer (p3) by obtaining the polymer (p5) by the method described in Japanese Patent Application No. 49-56 or Japanese Patent Application No. 2015-227178.
However, Polymer in the following formula (p0) is the remainder excluding the iodine atom of the precursor polymer, and the same applies to the following formulas. ^{X 1} in the formula (p3) and the following equation (p6) is the same as ^{X 1} in the above formula (g3).
Polymer-I (p0)
Polymer-CH ₂ CH ₂ I (p1)
Polymer-CH ₂ CH ₂ OH (p2)
_{^{Polymer-CH 2 CH 2 OCOCX 1}} = CH 2 (p3)
Polymer-CH ₂ CHICH ₂ OH (p4)
Polymer-CH ₂ CH ₂ CH ₂ OH (p5)
^{_{Polymer-CH 2 CH 2 CH 2}} OCOCX 1 = CH 2 (p6)
As a method for converting the iodine atom of the precursor polymer into a group having an epoxy group, a polymer (p4) is obtained by the same method as described above, and described in JP-B-46-25361 or JP-B-60-55490. The method of obtaining a polymer (p7) by the method of is mentioned. Ep in the formula (p7) is an epoxy group.
Polymer-CH ₂ Ep (p7)
As a method of converting the iodine atom of the precursor polymer into a group having a vinyl group, a polymer (p1) is obtained by the same method as described above, and Journal of Fluorine Chemistry, 1995, Vol. 74, No. 2, p. The method of obtaining a polymer (p8) by the method of 191-197 is mentioned.
In addition, Journal of Fluorine Chemistry, 1982, Vol. 20, No. 3, p. Examples thereof include a method of obtaining a polymer (p9) from a polymer (p0) by the method described in 313-327 and further obtaining a polymer (p10) by a method described in JP-A-48-34805.
Tetrahedron Letters, 2001, Vol. 42, No. 5, p. The polymer (p10) may be obtained from the polymer (p0) by the method described in 947-950.
Polymer-CH═CH ₂ (p8)
Polymer-CH ₂ CHICH ₂ OCOCH ₃ (p9)
Polymer-CH ₂ CH═CH ₂ (p10)
As a method for converting the iodine atom of the precursor polymer into a group having a group (g4), Journal of Organic Chemistry, 1962, Vol. 27, p. The polymer (p11) is obtained from the polymer (p0) by the method described in 2261-2262, JP-A-5-339007 or International Publication No. 2012/081524, and International Publication No. 2012/081524 or International Publication No. 2013. The method of obtaining a polymer (p12) by the method of / 031622 is mentioned.
Also, Journal of Fluorine Chemistry, 2000, Vol. 104, No. 2, p. You may obtain a polymer (p12) from a polymer (p8) by the method as described in 185-194, international publication 2012/081524, or Unexamined-Japanese-Patent No. 2015-205973.
Journal of Fluorine Chemistry, 2000, Vol. 104, No. 2, p. The polymer (p13) may be obtained from the polymer (p10) by the method described in 185-194.
However, the following equation (pi 1), the ^{X 2} and ^{R 5} in the formula (p12) and the following formula (p13), the same as ^{X 2} and ^{R 5} in the formula (g4).
Polymer-CH ₂ CHISiX ² _n (OR ⁵ ) _3-n (p11)
Polymer-CH ₂ CH ₂ SiX ² _n (OR ⁵ ) _3-n (p12)
Polymer-CH ₂ CH ₂ CH ₂ SiX ² _n (OR ⁵ ) _3-n (p13)

  What is necessary is just to adjust suitably the number of crosslinkable groups per polymer molecule in a fluorine-containing polymer (A1) according to the balance of the crosslinkability of a fluorine-containing polymer (A1) and each characteristic as a fluorine-containing polymer. If the number of crosslinkable groups per polymer molecule is large, the crosslinkability of the fluoropolymer (A1) is further improved. If the number of crosslinkable groups per polymer molecule does not increase too much, it is difficult to impair each characteristic as a fluorine-containing polymer.

As the fluorine-containing polymer (A1), it is preferable that all units of the fluorine-containing polymer (A1) are units based on a perfluoromonomer or iodine-containing perfluoromonomer from the viewpoint of excellent properties as a fluorine-containing polymer.
As the fluorine-containing polymer (A1), those having a branched molecular chain are preferred from the viewpoint that the number of crosslinkable groups introduced at the ends of the molecular chain is large and the crosslinkability and solubility are excellent.

  The mass average molecular weight of the fluoropolymer (A1) is preferably from 5,000 to 80,000, more preferably from 10,000 to 60,000, and even more preferably from 15,000 to 40,000. If the mass average molecular weight of the fluoropolymer (A1) is not less than the lower limit of the above range, the fluorine content in the fluoropolymer (A1) will be high, and the characteristics as the fluoropolymer (A1) will be sufficiently developed. . Further, when the fluoropolymer (A1) is cured by a crosslinking reaction, the strength of a cured product such as a film or a coating film tends to be good. When the mass average molecular weight of the fluoropolymer (A1) is not more than the upper limit of the above range, the solubility of the fluoropolymer (A1) in the solvent tends to be good, and a solution having a high polymer concentration is easily obtained. Further, when the fluoropolymer (A1) is cured by a crosslinking reaction, the reactivity tends to be good.

In the production method of the fluorine-containing polymer having a crosslinkable group of the present invention described above, the monomer (m1) having a fluorine atom and an iodine atom, and the monomer having a fluorine atom and not having an iodine atom (m2) ) To obtain a precursor polymer having one or both of the group (g1) and the group (g2), and converting the iodine atom of the precursor polymer into a group having a crosslinkable group Since this is a method for obtaining the fluorine-containing polymer (A1), as in the conventional method (method of polymerizing a monomer having a fluorine atom and a monomer having no cross-linkable group without a fluorine atom), a fluorine-containing polymer ( There is no need to reduce the proportion of units based on monomers having a fluorine atom in A1). Therefore, it is possible to produce a fluorine-containing polymer (A1) in which each characteristic (low dielectric constant, low refractive index, transparency, water / oil repellency, heat resistance, light resistance, chemical stability, gas permeability, etc.) is not impaired. . Moreover, the iodine atom which exists in the terminal group of a precursor polymer can be converted into various crosslinkable groups. By selecting a crosslinkable group according to the application, there is no particular limitation on the application, but it can be applied to various applications such as electronic members, optical members, water / oil repellency-imparting agents, release agents, biochips and the like. A fluorine-containing polymer (A1) can be obtained.
In the method for producing a fluoropolymer having a crosslinkable group of the present invention described above, a precursor polymer having a plurality of iodine atoms is obtained, and the iodine atoms of the precursor polymer are converted into groups having a crosslinkable group. Since this is a method of obtaining a fluoropolymer (A1) by conversion, compared with the conventional method (method of introducing a trimethoxysilyl group at the end of a fluoropolymer having an aliphatic ring structure consisting of a linear molecular chain) Many crosslinkable groups can be introduced. Therefore, the fluoropolymer (A1) excellent in crosslinkability and solubility can be produced.

<Method for producing curable composition>
The manufacturing method of the curable composition of this invention is a method of obtaining a fluorinated polymer (A1) by the method mentioned above, and preparing the curable composition containing this fluorinated polymer (A1).

When the fluoropolymer (A1) has a group (g3) or a vinyl group as a crosslinkable group, the curable composition includes a photocurable composition containing the fluoropolymer (A1) and a photopolymerization initiator; Examples thereof include a thermosetting composition containing a fluorine-containing polymer (A1) and a thermal polymerization initiator; a curable composition containing a fluorine-containing polymer (A1), a hydrosilylation crosslinking agent, and a hydrosilylation catalyst.
As a photoinitiator, the thing as described in Unexamined-Japanese-Patent No. 2008-189836, international publication 2013/115191, etc. are mentioned.
Examples of the thermal polymerization initiator include known radical initiators.
Examples of the hydrosilylation crosslinking agent and the hydrosilylation catalyst include those described in International Publication No. 2011/065155.

When the fluoropolymer (A1) has a group (g4) as a crosslinkable group, the curable composition includes a photocurable composition containing the fluoropolymer (A1) and a photoacid generator or photobase generator. Thing etc. are mentioned.
Examples of the photoacid generator include those described in JP-A No. 2006-169375, International Publication No. 2015/033805, International Publication No. 2015/163379, and the like.
Examples of the photobase generator include those described in International Publication No. 2015/033805.
The curable composition may contain alkoxysilane (tetraalkoxysilane, trialkoxysilane, dialkoxysilane, etc.) as a crosslinking agent.

When the fluorine-containing polymer (A1) has an epoxy group as a crosslinkable group, examples of the curable composition include a curable composition containing the fluorine-containing polymer (A1) and an epoxy curing agent.
As the epoxy curing agent, for example, various curing agents described in the epoxy resin handbook (Nikkan Kogyo Shimbun, published in 1987) can be used. Specific examples include amine curing agents, polyaminoamide curing agents, acid and acid anhydride curing agents, and the like.

The curable composition may contain an additive as necessary within a range not impairing the effects of the present invention.
Additives include surfactants, thixotropic agents, antifoaming agents, antioxidants, UV absorbers, light stabilizers, other polymers, oligomers, reactive diluents (monomers), silane coupling agents, fillers , Solvent and the like.

In the manufacturing method of the curable composition of the present invention described above, the method of preparing the curable composition containing the fluorine-containing polymer (A1) by obtaining the fluorine-containing polymer (A1) by the above-described method. Therefore, it is possible to produce a curable composition that does not impair each characteristic as a fluorine-containing polymer and is excellent in curability and compatibility of each component.
Since the fluorine-containing polymer (A1) has many hydrocarbon-based crosslinkable groups, it is easily dissolved not only in a solvent having a high fluorine content but also in a solvent or a reactive diluent having a low fluorine content. Therefore, a wide variety of solvents and reactive diluents can be selected in the curable composition. According to the curable composition in which the fluorine-containing polymer (A1) is dissolved in a solvent or a reactive diluent, it is easy to form a uniform coating film by coating. Moreover, since the fluoropolymer (A1) has a crosslinkable group, the formed coating film has good adhesion to the substrate.

<Fluorine-containing polymer having a crosslinkable group>
The fluorinated polymer having a crosslinkable group according to an embodiment of the present invention comprises a branched molecular chain having a unit having a fluorine atom, and has a fluorinated polymer having a crosslinkable group at a plurality of terminals of the branched molecular chain (hereinafter referred to as a fluorinated polymer). (Also referred to as a fluoropolymer (A2)). At least a part of the unit having a fluorine atom is preferably a unit having a fluorine atom and an aliphatic ring structure. The crosslinkable group may be present at some terminals of the branched molecular chain, or may be present at all terminals of the branched molecular chain.

Examples of the unit having a fluorine atom include a unit based on the monomer (m1) and a unit based on the monomer (m2).
The unit based on the monomer (m1) includes a unit (branch point) obtained by removing an iodine atom from the unit based on the monomer (m1), and the iodine atom of the unit based on the monomer (m1) is a crosslinkable group. Also included are those converted to groups having Moreover, the unit based on the monomer (m2) includes those in which a group having a crosslinkable group is bonded to the unit based on the monomer (m2).

  As the unit based on the monomer (m1), the fluorine-containing polymer (A2) can be increased in the fluorine-containing polymer (A2), and a fluorine-containing polymer (A2) having excellent properties as a fluorine-containing polymer can be obtained. Units based on are preferred.

  As the unit based on the monomer (m2), the fluorine-containing polymer (A2) can be increased in the fluorine-containing polymer (A2), and a fluorine-containing polymer (A2) having excellent properties as a fluorine-containing polymer can be obtained. Units are preferred.

  As the unit based on the monomer (m2), the fluorine-containing polymer (A2) has a fluorine atom from the viewpoint that the fluorine-containing polymer (A2) is excellent in solubility in a solvent and has excellent properties as a fluorine-containing polymer. And a unit having an aliphatic ring structure is preferred.

Examples of the unit having a fluorine atom and an aliphatic ring structure include a unit based on the monomer (m20), a unit based on the monomer (m22), and a unit based on the monomer (m23). From the viewpoint that it can be a unit having g12), a unit based on the monomer (m20) or a unit based on the monomer (m23) is preferred.
The unit based on the monomer (m20) is preferably a unit based on the monomer (m21) from the viewpoint of polymerization reactivity and ease of synthesis.

  Examples of the unit based on the monomer (m21) include units based on the monomers (m21-1) to (m21-7).

  Examples of the unit based on the monomer (m22) include units based on the monomers (m22-1) to (m22-2), and the unit based on the monomer (m22-1) from the viewpoint of easy monomer synthesis. Is preferred.

A unit based on the monomer (m23) is represented by the following formula (u23). Examples of the unit based on the monomer (m23) include units based on the monomers (m23-1) to (m23-3), and the unit based on the monomer (m23-1) from the viewpoint of easy monomer synthesis. Is preferred.
R ^{31 to} R ^{36 in the} unit represented by the formula (u23) are the same as those in the monomer (m23), and preferred forms are also the same.

The unit based on the monomer (m1) and the unit based on the monomer (m2) are appropriately selected so that the fluoropolymer (A2) has one or both of the group (g11) and the group (g12). It is preferable.
The fluorine-containing polymer (A2) may have a unit based on a third monomer other than the monomer (m1) and the monomer (m2) as necessary, as long as the effects of the present invention are not impaired. Examples of the third monomer include those similar to those in the precursor polymer described above.

  The preferable range of the molar ratio (m2 / m1) of the unit based on the monomer (m2) to the unit based on the monomer (m1) in the fluoropolymer (A2) is the same as the preferable range of m2 / m1 in the precursor polymer described above. .

The fluorine-containing polymer (A2) is obtained, for example, by converting iodine atoms of a precursor polymer having a branched molecular chain into a group having a crosslinkable group among the aforementioned precursor polymers.
As the fluorine-containing polymer (A2), those in which all of the iodine atoms of the precursor polymer react and do not contain iodine atoms are preferable, and those having a high conversion rate of iodine atoms to groups having a crosslinkable group are preferable. . If iodine atoms remain in the fluorine-containing polymer (A2), the fluorine-containing polymer (A2) is easily deteriorated and colored by iodine released by light or heat.

As the fluorine-containing polymer (A2), from the viewpoint of excellent crosslinkability and solubility, the fluorine-containing polymer having one or both of the group (g11) and the group (g12), that is, the fluorine-containing polymer (A1) described above. Of these, those corresponding to the fluorine-containing polymer (A1) having a branched molecular chain are preferred.
Examples of the crosslinkable group include the same crosslinkable groups as those in the fluorine-containing polymer (A1) described above, and preferred forms are also the same.

What is necessary is just to adjust suitably the number of crosslinkable groups per polymer molecule in a fluorine-containing polymer (A2) according to the balance of the crosslinkability of a fluorine-containing polymer (A2) and each characteristic as a fluorine-containing polymer. If the number of crosslinkable groups per polymer molecule is large, the crosslinkability of the fluoropolymer (A2) is further improved. If the number of crosslinkable groups per polymer molecule does not increase too much, it is difficult to impair each characteristic as a fluorine-containing polymer.
As the fluorine-containing polymer (A2), it is preferable that all units of the fluorine-containing polymer (A2) are units based on a perfluoromonomer or iodine-containing perfluoromonomer from the viewpoint of excellent properties as a fluorine-containing polymer.
The preferred range of the mass average molecular weight of the fluoropolymer (A2) is the same as the preferred range of the mass average molecular weight of the fluoropolymer (A1) described above.

Since the fluoropolymer having a crosslinkable group according to the embodiment of the present invention described above is a polymer having a unit having a fluorine atom, each characteristic as the fluoropolymer (low dielectric constant, low refractive index) , Transparency, water / oil repellency, heat resistance, light resistance, chemical stability, gas permeability, etc.).
In addition, the fluorine-containing polymer having a crosslinkable group according to the embodiment of the present invention described above is a fluorine-containing polymer having a branched molecular chain and having a crosslinkable group at a plurality of ends of the branched molecular chain. Therefore, it is excellent in crosslinkability and solubility. That is, when the fluoropolymer (A2) has a branched structure, crosslinkability is improved and solubility is also improved. When the fluoropolymer (A2) has many crosslinkable groups, the crosslinkability is improved and the solubility is also improved.

<Curable composition>
The curable composition which concerns on embodiment of this invention is a curable composition containing the fluorine-containing polymer (A2) which concerns on embodiment of this invention.

  The curable composition according to the embodiment of the present invention includes the curable composition exemplified in the above-described method for producing a curable composition except that the fluorine-containing polymer (A1) is replaced with the fluorine-containing polymer (A2). The same thing is mentioned, A preferable form is also the same.

  In the curable composition which concerns on embodiment of this invention demonstrated above, since the fluorine-containing polymer (A2) which concerns on embodiment of this invention is included, each characteristic as a fluorine-containing polymer is not impaired, and sclerosis | hardenability. And excellent compatibility with other components constituting the curable composition.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples. Examples 1-5 are examples.

(Molar ratio of units)
About the molar ratio of each unit in a precursor polymer, the iodine content was calculated | required by the elemental analysis, and it computed from the iodine content.
Since the molar ratio of each unit in the fluoropolymer (A1) corresponds to the molar ratio of the units in the precursor polymer, the description is omitted.

(Mass average molecular weight)
The mass average molecular weight of the precursor polymer or the fluoropolymer (A1) was determined by Method i or Method ii shown below.
Method i:
The mass average molecular weight of the polymer in terms of PMMA was determined using a GPC measuring apparatus (HLC-8320GPC, manufactured by Tosoh Corporation). As the solvent, Asahi Clin AK-225 SEC Grade-1 manufactured by Asahi Glass Co., Ltd. was used. As the column, two PLgel 5μ MIXED-C (manufactured by Polymer Laboratories) were connected in parallel. The measurement temperature was 40 ° C. An evaporative light scattering detector was used as the detector.
Method ii:
Using a solvent in which HFC-52-13p, HCFC-225cb and 1,1,1,3,3,3-hexafluoroisopropyl alcohol were mixed at a volume ratio of 40: 55: 5 as a solvent, the measurement temperature was 37 ° C. The PMMA-converted mass average molecular weight of the polymer was determined in the same manner as in method i, except that

The materials used in the examples are as follows.
(monomer)
PDD: monomer (m21-1).

BVE: monomer (m23-1).
_{CF 2 = CF-O-CF} 2 -CF 2 -CF = CF 2 (m23-1)
8IVE:
_{CF 2 = CFOCF 2 CF (CF} 3) OCF 2 CF 2 -I

(Radical initiator)
IPP: diisopropyl peroxydicarbonate.
(solvent)
HFC-52-13p: CF ₃ (CF ₂ ) ₅ H,
HCFC-225cb: CClF ₂ CF ₂ CHClF,
_{AE-3000: CF 3 CH 2} OCF 2 CF 2 H.
(Other)
_{PHVE-I: CF 3 CF 2} CF 2 OCF (CF 3) CF 2 OCF 2 CF 2 -I

(Synthesis of 8IVE)
8IVE is described in Huaxue Xuebao, 47, No. 7, 1989, p. The compound was synthesized by the following two-step reaction in the same manner as described in 720-723. The purity by gas chromatography was 99.8% (bp. 62-63 ° C./6.7 kPa).

(Example 1)
Production of precursor polymer:
In a 120 mL Hastelloy autoclave with an internal volume of 120 mL, 3.36 g of 8IVE was charged. A solution prepared by dissolving 0.707 g of IPP in about 10 g of HFC-52-13p and 36.24 g of BVE were added, and then the HFC-52-13p added to the autoclave was 79.69 g. -52-13p was added. After freeze-deaeration was repeated twice using liquid nitrogen, the temperature was returned to about 0 ° C., and nitrogen gas was introduced to 0.3 MPaG (G represents a gauge pressure; the same applies hereinafter). The autoclave was set in a water bath and stirred for 7 hours while maintaining the internal temperature at 45 ° C., and then the autoclave was immersed in ice water and cooled to 20 ° C. or lower to stop the reaction.
The reaction solution was transferred from the autoclave to a beaker, and about 33 g of HFC-52-13p was added. About 180 g of n-hexane was added, stirred for 30 minutes, and allowed to stand overnight. After decantation, about 125 g of HFC-52-13p was added to dissolve the polymer, and about 180 g of n-hexane was added and stirred for 30 minutes to aggregate the polymer, followed by decantation. The same operation was repeated two more times. It was vacuum-dried at 60 ° C. for 11 days to obtain 14.2 g of a white polymer (p0-1). Table 1 shows the iodine content determined by elemental analysis, the molar ratio of the unit based on BVE to the unit based on 8VE (m2 / m1), and the mass average molecular weight determined by Method i for the polymer (p0-1). The absolute mass average molecular weight of the polymer (p0-1) measured by GPC (hereinafter referred to as “GPC-MALS method”) equipped with a multi-angle light scattering detector is 33,200.
When ¹⁹ F-NMR was measured by dissolving the polymer (p0-1) in HCFC-225cb, the ratio of the unit based on BVE to which the iodine atom was bonded to the unit based on 8IVE in which the iodine atom was not dissociated was − The ratio of the peak of 45 to -56 ppm and the peak around -64 ppm was found to be 24:76, and it was confirmed that the polymer (p0-1) was a branched molecular chain.

Production of fluoropolymer (A1):
A solution in which the polymer (p0-1) is dissolved in HCFC-225cb so as to have a concentration of 6% by mass, a solution in which IPP is diluted 400 times by mass with HCFC-225cb, and allyl alcohol is 300 times by mass in HCFC-225cb A diluted solution was prepared.
The above solutions were made in this order in a volume of 34 mL of Hastelloy so that the polymer (p0-1) was 1.20 g (0.185 mmol as the number of moles of iodine), 10.8 mg of allyl alcohol, and 7.6 mg of IPP. Added to autoclave. Finally, HCFC-225cb was added so that the total amount of HCFC-225cb was 28.78 g. After freeze degassing was repeated twice using liquid nitrogen, the internal temperature of the autoclave was returned to about 0 ° C., and nitrogen gas was introduced until the pressure reached 0.2 MPaG. The autoclave was set in a water bath and stirred at 45 ° C. for 1 hour, 50 ° C. for 2 hours, and 60 ° C. for 2 hours. The autoclave was removed from the water bath and allowed to stand overnight to obtain a reaction solution containing the polymer (p4-1). When about 1 g of the reaction solution was sampled and ¹⁹ F-NMR and ¹ H-NMR were measured, the reaction rate of iodine end was 82.1%, and the conversion rate of iodine end to —CH ₂ CHICH ₂ OH was It was 74.8%.

A mixture of 38.2 mg of IPP and 0.600 g of n-hexane and 0.3 g of HCFC-225cb was added to the reaction solution, and the autoclave was sealed, followed by freezing and degassing using liquid nitrogen. Repeated times. The internal temperature of the autoclave was returned to about 0 ° C., and nitrogen gas was introduced to 0.3 MPaG. The autoclave was set in a water bath and stirred at 75 ° C. for 7 hours, and then the autoclave was taken out of the water bath and allowed to stand overnight. Using HCFC-225cb as a washing solvent, transfer the reaction solution in the autoclave to an eggplant flask, concentrate it with an evaporator until the polymer concentration becomes about 7%, add 20 g of n-hexane to agglomerate the polymer, and suck Filtered. About 10 g of HCFC-225cb was added to dissolve the polymer, and then 20 g of n-hexane was added to aggregate the polymer, followed by filtration. After repeating the same operation once again, it was vacuum-dried at 60 ° C. for 3 days. 1.12 g of a white polymer (p5-1) was obtained. When the polymer (p5-1) was dissolved in HCFC-225cb and ¹⁹ F-NMR and ¹ H-NMR were measured, the iodine terminal reaction rate of the polymer (p0-1) was 100%, and the polymer (p0-1 ) To iodine-terminated —CH ₂ CH ₂ CH ₂ OH was 47.3%.

0.349 g of polymer (p5-1), 9.8 mg of acrylic acid chloride, 10.9 mg of triethylamine and 8.36 g of HCFC-225cb were added to a glass container. As acrylic acid chloride and triethylamine, a solution diluted with HCFC-225cb at a mass ratio of 100 times was used. After stirring at room temperature for 3 hours, the mixture was allowed to stand overnight. In order to remove the precipitated solid, filtration was performed using a syringe equipped with a filter having a pore diameter of 0.45 μm. The filtrate was colorless and transparent. After concentration by an evaporator until the polymer concentration was about 7% by mass, about 6 g of hexane was added to aggregate the polymer. After suction filtration, the polymer was dissolved in HCFC-225cb, the insoluble matter was filtered in the same manner as before, the polymer was aggregated with about 6 g of hexane, and suction filtered. The same operation was repeated once again. The obtained polymer was dissolved in perfluorobenzene, and the insoluble matter was removed with a syringe with a filter in the same manner as described above. The solvent was distilled off using an evaporator, and perfluorobenzene was added to replace the solvent to obtain 4.69 g of a solution containing the polymer (p6-1). After this solution was washed with the same volume of water, the lower layer was measured by ¹ H-NMR. As a result, —CH ₂ CH ₂ CH ₂ OH was quantitatively converted to —CH ₂ CH ₂ CH ₂ OCOCH═CH _2. It was.

(Example 2)
Production of fluoropolymer (A1):
A solution obtained by dissolving the polymer (p0-1) obtained in Example 1 in HCFC-225cb at a concentration of 7.7% by mass, a solution in which allyl alcohol is diluted with HCFC-225cb at a mass ratio of 100 times, and IPP in HCFC-225cb A solution diluted to a mass ratio of 200 was prepared.
The above solutions were made in this order in a Hastelloy product with an internal volume of 120 mL so that 6.29 g of polymer (p0-1) (0.952 mmol in terms of moles of iodine), 66.3 mg of allyl alcohol, and 39.3 mg of IPP were obtained. Added to autoclave. Finally, HCFC-225cb was added so that the total amount of HCFC-225cb was 103.60 g. After freeze-deaeration was repeated twice using liquid nitrogen, the temperature was returned to about 0 ° C., and nitrogen gas was introduced until the pressure reached 0.2 MPaG. The autoclave was set in a water bath and stirred at 45 ° C. for 1 hour, 50 ° C. for 2 hours, and 60 ° C. for 2 hours. The autoclave was removed from the water bath and allowed to stand overnight to obtain a reaction solution containing the polymer (p4-2). When about 1 g of the reaction solution was sampled and ¹⁹ F-NMR and ¹ H-NMR were measured, the reaction rate of iodine terminal was 80.6%, and the conversion rate of iodine terminal to —CH ₂ CHICH ₂ OH was It was 80.2%.
Using HCFC-225cb as a washing solvent, the reaction solution in the autoclave was transferred to an eggplant flask. The amount of liquid in the flask was 123 g. 150 g of hexane was added and stirred, the polymer was agglomerated and suction filtered. About 100 g of HCFC-225cb was added to the obtained polymer to dissolve it, and it was agglomerated with about 150 g of hexane, followed by suction filtration. This operation was repeated once more. It vacuum-dried at 60 degreeC for 58 hours, and obtained 5.95 g of the white polymer (p4-2).

A solution in which IPP was diluted with HCFC-225cb to a mass ratio of 500 and a solution in which Bu ₃ SnH was diluted with HCFC-225cb to a mass ratio of 2 were prepared.
To a 100 mL four-necked flask equipped with a stirrer, a Dimroth, and a thermometer, 5.15 g of the polymer (p4-2) and 61.54 g of HCFC-225cb were added and stirred to dissolve the polymer. Then, IPP of 0.161 _g, such that the 3.40g of Bu 3 SnH, was added the above solution. Subsequently, HCFC-225cb was added to make the total amount of HCFC-225cb 81.44 g. After sealing the flask, freeze degassing was repeated twice using liquid nitrogen. After deaeration, nitrogen gas was introduced when the internal temperature of the flask was returned to room temperature in a water bath, and the inside of the flask was returned to normal pressure. The flask was set in a water bath and stirred at 50 ° C. for 2 hours under a nitrogen atmosphere. The flask was removed from the water bath and cooled to room temperature.
The reaction liquid in the flask was transferred to a beaker using HCFC-225cb as a washing solvent. The amount of liquid in the beaker was 105 g. About 130 g of hexane was added and stirred to coagulate the polymer and suction filtered. The obtained polymer was dissolved in about 100 g of HCFC-225cb, the polymer was aggregated with about 130 g of hexane, and suction filtered. The dissolution, flocculation and filtration operations of this polymer were repeated once more. It vacuum-dried at 60 degreeC for 12 hours, and 4.62 g of white polymer (p5-2) was obtained. When ¹⁹ F-NMR and ¹ H-NMR were measured by dissolving the polymer (p5-2) in HCFC-225cb, the iodine terminal reaction rate of the polymer (p0-1) was 100%, and the polymer (p4-2 the reaction rate of -CHI- of) is also 100%, conversion of the iodine end of the polymer (p0-1) to _-CH 2 _CH 2 _CH 2 OH was 72.4%.

A solution obtained by diluting acrylic acid chloride with HCFC-225cb at a mass ratio of 80 times, a solution obtained by diluting triethylamine with HCFC-225cb at a mass ratio of 80 times, and a solution obtained by diluting 4-methoxyphenol with HCFC-225cb at a mass ratio of 800 times. Prepared.
0.450 g of the polymer (p5-2) and 6.49 g of HCFC-225cb were added to a glass container having an internal volume of 30 mL, and the mixture was stirred and dissolved. Next, 0.135 g of 4-methoxyphenol solution, 1.97 g of acrylic acid chloride solution, triethylamine so that 4-methoxyphenol, acrylic acid chloride, and triethylamine were 0.0014 mmol, 0.272 mmol, and 0.272 mmol, respectively. 2.21 g of the solution was added in this order. After stirring at room temperature for 3 hours, the mixture was allowed to stand overnight. The precipitated solid was removed by filtration with a filter having a pore size of 0.45 μm. From the obtained filtrate, the solvent was distilled off with an evaporator without heating to obtain a polymer. 10 g of a mixed solvent of methanol / water (mass ratio 9/1) was added to the polymer and stirred, and the polymer was washed and suction filtered. The same operation was repeated twice, then washed with 10 g of methanol and filtered. The obtained polymer was vacuum-dried at room temperature to obtain a polymer (p6-2). When dissolved in perfluorobenzene so that the polymer concentration was 7% by mass and measured by ¹ H-NMR, —CH ₂ CH ₂ CH ₂ OH was almost quantitatively converted to —CH ₂ CH ₂ CH ₂ OCOCH═CH ₂ . It was confirmed that it was converted.

(Example 3)
Production of fluoropolymer (A1):
A solution obtained by dissolving the polymer (p0-1) obtained in Example 1 in HCFC-225cb at a concentration of 6% by mass, a solution obtained by diluting IPP with HCFC-225cb at a mass ratio of 400 times, and dimethoxymethylvinylsilane with HCFC-225cb A solution diluted to a mass ratio of 50 was prepared.
The above solution was placed in this order in order of 1.20 g of polymer (p0-1) (0.185 mmol as the number of moles of iodine), 7.6 mg of IPP, and 49.0 mg of dimethoxymethylvinylsilane in this order. Added to the autoclave. Finally, HCFC-225cb was added so that the total amount of HCFC-225cb was 28.74 g. After freeze-degassing was repeated twice using liquid nitrogen, the internal temperature of the autoclave was returned to about 0 ° C., and nitrogen gas was introduced until the pressure reached 0.2 MPaG. The autoclave was set in a water bath and stirred at 50 ° C. for 2 hours, 60 ° C. for 2 hours, and 70 ° C. for 2 hours. The autoclave was taken out of the water bath and allowed to stand overnight to obtain a reaction solution containing the polymer (p11-1). When about 1 g of the reaction solution was sampled and ¹⁹ F-NMR and ¹ H-NMR were measured, the reaction rate at the iodine terminal was 100%, and the iodine terminal was converted to —CH ₂ CHISiCH ₃ (OCH ₃ ) ₂ . The conversion rate was 80.5%, and the conversion rate of iodine-terminated —CH ₂ CH ₂ SiCH ₃ (OCH ₃ ) ₂ was 15.5%.

A mixture of 19.1 mg of IPP and 0.300 g of n-hexane and 0.3 g of HCFC-225cb was added to the reaction solution, and the autoclave was sealed, and then freeze degassing was performed using liquid nitrogen. Repeated times. The internal temperature of the autoclave was returned to about 0 ° C., and nitrogen gas was introduced to 0.3 MPaG. The autoclave was set in a water bath and stirred at 75 ° C. for 7 hours, and then the autoclave was taken out of the water bath and allowed to stand overnight. About 1 g of the obtained reaction solution was sampled and ¹⁹ F-NMR and ¹ H-NMR were measured. As a result, it was confirmed that the —CHI— peak was almost eliminated. Using HCFC-225cb as a washing solvent, the reaction solution in the autoclave was transferred to an eggplant flask and concentrated with an evaporator. The liquid volume after concentration was 17 g. About 50 g of AE-3000 was added to agglomerate, and suction filtered. The obtained polymer was dissolved in about 15 g of HCFC-225cb, aggregated by adding about 50 g of AE-3000, and suction filtered. The resultant polymer was dissolved in about 15g of HCFC-225cb, to obtain a solution of _-CH 2 _CH 2 SiCH ₃ to the end _{(OCH 3)} polymers having _{2 (p12-1).}

(Example 4)
Production of precursor polymer:
To a stainless steel autoclave having an internal volume of 110 mL, a solution prepared by dissolving 2.98 g of 8IVE and 0.15 g of IPP in about 5 g of HCFC-225cb and 13.37 g of PDD were added, and finally HCFC-225cb was added. The total amount of HCFC-225cb added was 61.78 g. After freeze degassing was repeated twice using liquid nitrogen, the temperature was returned to about 0 ° C., and nitrogen gas was introduced to 0.3 MPaG. The autoclave was set in a water bath and stirred for 8 hours while maintaining the internal temperature at 45 ° C., and then the autoclave was immersed in ice water and cooled to 20 ° C. or lower to stop the reaction.
The jelly-like product was transferred from the autoclave to a beaker, and HCFC-225cb was added so that the total amount was 128 g. After stirring with a magnetic stirrer for 30 minutes, 150 g of n-hexane was added to agglomerate the polymer, followed by stirring for 30 minutes. After filtration under reduced pressure, the obtained polymer was washed with n-hexane. The washed polymer was returned to the beaker, HCFC-225cb was added until the total amount became 128 g, and the mixture was stirred for 30 minutes. 150 g of n-hexane was added and stirred for 30 minutes to aggregate the polymer. The polymer obtained by suction filtration was washed with n-hexane, and the same operation was repeated again. Then, it vacuum-dried until it became constant weight at 60 degreeC, and obtained 12.4g of the polymer (p0-2) of white powder. Table 1 shows the iodine content determined by elemental analysis for the polymer (p0-2), the molar ratio of the unit based on PDD to the unit based on 8IVE (m2 / m1), and the PMMA equivalent mass average molecular weight determined by method ii. . The absolute mass average molecular weight of the polymer (p0-2) by GPC-MALS method is 64,100.
When ¹⁹ F-NMR was measured by dissolving the polymer (p0-2) in perfluorobenzene, it was found that there was a unit based on PDD to which an iodine atom was bonded, and the polymer (p0-2) was a branched molecular chain. It was confirmed. The ratio of the unit based on PDD to which the iodine atom is bonded to the unit based on 8IVE in which the iodine atom is not dissociated is −42 to −47 ppm of ¹⁹ F-NMR (the chemical shift of perfluorobenzene is set to −162.7 ppm). It was found that the ratio was 50:50 from the ratio of the peak of ˜ and the peak around −62 ppm.

Production of fluoropolymer (A1):
A solution prepared by dissolving HCFC-225cb so that the polymer (p0-2) is 4% by mass, a solution obtained by diluting PHVE-I with HCFC-225cb at a mass ratio of 10 times, and IPP at a mass ratio of 100 times with HCFC-225cb A diluted solution and a solution in which allyl alcohol was diluted with HCFC-225cb at a mass ratio of 100 times were prepared.
The above solution was added in this order so that 2.40 g of polymer (p0-2) (0.415 mmol as the number of moles of iodine), 72.4 mg of allyl alcohol, 42.8 mg of IPP, and 360 mg of PHVE-I were obtained. It added to the Hastelloy autoclave with an internal volume of 120 mL. Finally, HCFC-225cb was added so that the total amount of HCFC-225cb was 117.13 g. Using liquid nitrogen, freeze deaeration was repeated twice, and then the temperature was returned to about 0 ° C., and nitrogen gas was introduced to 0.2 MPaG. The autoclave was set in a water bath and stirred at 50 ° C. for 2 hours, 60 ° C. for 2 hours, and 70 ° C. for 1 hour.
Using HCFC-225cb as the washing solvent, the reaction solution of the autoclave was transferred to the eggplant flask. The amount of liquid in the flask was 133 g. 166 g of hexane was added and stirred to agglomerate the polymer and suction filtered. About 120 g of HCFC-225cb was added to the obtained polymer to dissolve it, and about 170 g of hexane was added to aggregate the polymer, followed by suction filtration. The same operation was repeated once more. 60 3 days vacuum drying at ° C., to obtain a 2.23g of _CF 3 _CF 2 _CF 2 _OCF traces _{(CF 3)} white polymer containing _{CF 2 CH 2 CHICH 2 OH (} p4-3). When the polymer (p4-3) was dissolved in HCFC-225cb and ¹⁹ F-NMR and ¹ H-NMR were measured, the reaction rate of terminal iodine was 82.6%, and —CH ₂ CHICH ₂ OH of terminal iodine The conversion to was 73.7%. Note that in the product, with respect to 100 parts by weight of the polymer _{(p4-3), CF 3 CF 2} CF 2 OCF (CF 3) CF 2 CH 2 CHICH 2 OH was contained 4.1 parts by weight .

A solution obtained by diluting IPP with HCFC-225cb to a mass ratio of 200 times and a solution obtained by diluting Bu ₃ SnH with HCFC-225cb to a mass ratio of 1.5 times were prepared.
To a 50 mL four-necked flask equipped with a stirrer, a Dimroth, and a thermometer, 1.00 g of the polymer (p4-3) and 22.15 g of HCFC-225cb were added and stirred to dissolve the polymer. Then, IPP of 3.6 _mg, was added the solution to a 757mg of Bu 3 SnH. HCFC-225cb was then added. The total amount of HCFC-225cb was 23.24 g. After sealing the flask, freeze degassing was repeated twice using liquid nitrogen. After deaeration, nitrogen gas was introduced when the internal temperature of the flask was returned to room temperature in a water bath, and the inside of the flask was returned to normal pressure. The flask was set in a water bath and stirred at 50 ° C. for 2 hours under a nitrogen atmosphere. The flask was removed from the water bath and cooled to room temperature.
The reaction liquid in the flask was transferred to a beaker using HCFC-225cb as a washing solvent. The amount of liquid in the beaker was 36.2 g. About 45 g of hexane was added and stirred to coagulate the polymer and suction filtered. The obtained polymer was dissolved in about 33 g of HCFC-225cb, the polymer was aggregated with about 45 g of hexane, and suction filtered. The dissolution, flocculation and filtration operations of this polymer were repeated once more. It vacuum-dried at 60 degreeC for 21 hours, and obtained 0.84g of white polymer (p5-3). When ¹⁹ F-NMR and ¹ H-NMR were measured by dissolving the polymer (p5-3) in HCFC-225cb, the iodine terminal reaction rate of the polymer (p0-2) was 100%, and the polymer (p4- the reaction rate of -CHI- 3) is 86.9% conversion of the iodine end of the polymer (P0-2) to the _-CH 2 _CH 2 _CH 2 OH was 63.9%.

A solution obtained by diluting acrylic acid chloride with HCFC-225cb at a mass ratio of 40 times, a solution obtained by diluting triethylamine with HCFC-225cb at a mass ratio of 40 times, and a solution obtained by diluting 4-methoxyphenol with HCFC-225cb at a mass ratio of 800 times. Prepared.
0.20 g of polymer (p5-3) and 3.67 g of HCFC-225cb were added to a glass container and stirred to dissolve. Next, 0.069 g of 4-methoxyphenol solution, 0.502 g of acrylic acid chloride solution, triethylamine so that 4-methoxyphenol, acrylic acid chloride, and triethylamine are 0.0007 mmol, 0.139 mmol, and 0.139 mmol, respectively. 0.561 g of the solution was added in this order. After stirring at room temperature for 3 hours, the mixture was allowed to stand overnight. The precipitated solid content was removed by filtration with a filter having a pore size of 5 μm. To the obtained filtrate, the same volume of water as the filtrate was added, washed twice, and the lower layer was dried over magnesium sulfate. Magnesium sulfate was removed by filtration to obtain a solution containing the polymer (p6-3). Was measured ¹ _H-NMR, the conversion of the -CH _{2 CH 2} CH ₂ OH to _{-CH 2 CH 2 CH 2 OCOCH =} CH 2 was 87.7%.

(Example 5)
Production of precursor polymer:
In the same manner as in Example 4, a polymer (p0-2) was obtained.

Production of fluoropolymer (A1):
The amount charged into the autoclave was the same as Example 4 except that the polymer (p0-2) was changed to 3.59 g, allyl alcohol 78.4 mg, PHVE-I 240 mg, and HCFC-225cb total amount 116.05 g. In this way, a polymer (p4-4) containing CF ₃ CF ₂ CF ₂ OCF (CF ₃ ) CF ₂ CH ₂ CHICH ₂ OH was obtained. When ¹⁹ F-NMR and ¹ H-NMR were measured by dissolving the polymer (p4-4) in HCFC-225cb, the reaction rate of terminal iodine was 84%, and the terminal iodine converted to —CH ₂ CHICH ₂ OH. The conversion rate was 78%. The product contained 2.1 parts by mass of CF ₃ CF ₂ CF ₂ OCF (CF ₃ ) CF ₂ CH ₂ CHICH ₂ OH with respect to 100 parts by mass of the polymer (p4-4). .

A solution in which IPP was diluted with HCFC-225cb to a mass ratio of 100 and a solution in which Bu ₃ SnH was diluted with HCFC-225cb to a mass ratio of 2 were prepared.
To a 50 mL four-necked flask equipped with a stirrer, a Dimroth, and a thermometer, 2.86 g of the polymer (p4-4) and 60.91 g of HCFC-225cb were added and stirred to dissolve the polymer. Then, IPP of 11.9 _mg, was added the solution to a 2.52g of Bu 3 SnH. HCFC-225cb was then added. The total amount of HCFC-225cb was 64.61 g. Thereafter, in the same manner as in Example 4, 2.69 g of a white polymer (p5-4) was obtained. The reaction rate of the iodine-terminated polymer (P0-2) was 100%, 100% even reaction rate -CHI- polymer (p4-4), _-CH 2 CH iodine end of the polymer (P0-3) The conversion to ₂ CH ₂ OH was 77%.

A solution obtained by diluting acrylic acid chloride with HCFC-225cb at a mass ratio of 10 times, a solution obtained by diluting triethylamine with HCFC-225cb at a mass ratio of 10 times, and a solution obtained by diluting 4-methoxyphenol with HCFC-225cb at a mass ratio of 500 times. Prepared.
In a glass container, 2.40 g of the polymer (p5-4) and 53.38 g of HCFC-225cb were added and stirred to dissolve. Next, 1.03 g of 4-methoxyphenol solution, 1.51 g of acrylic acid chloride solution, and triethylamine so that 4-methoxyphenol, acrylic acid chloride, and triethylamine were 0.0166 mmol, 1.66 mmol, and 1.66 mmol, respectively. 1.68 g of the solution was added in this order. Stir overnight at room temperature. The mixture was aggregated with 102 g of methanol, stirred for 30 minutes, and filtered under reduced pressure. To the obtained filtrate, 0.5 g of a solution obtained by diluting the 4-methoxyphenol with HCFC-225cb at a mass ratio of 500 times and HCFC-225cb were added to make the total amount 69 g. After stirring for 30 minutes, the polymer was re-agglomerated with 102 g of methanol, and the mixture was stirred for 30 minutes and filtered under reduced pressure. Further, the same operation as described above was performed again, and the mixture was aggregated with methanol and filtered under reduced pressure to obtain a solid content. To the obtained solid content, 0.5 g of a solution obtained by diluting the 4-methoxyphenol with HCFC-225cb at a mass ratio of 500 times and HCFC-225cb were added to make a total amount of 69 g, followed by stirring for 30 minutes. Next, 84 g of hexane was added and the polymer was agglomerated and stirred for 30 minutes and filtered under reduced pressure. This operation of dissolution / aggregation / filtration was further repeated twice, followed by vacuum drying overnight at room temperature to obtain 2.17 g of polymer (p6-4). ^{According to 19} F-NMR and ¹ H-NMR analysis, the conversion rate of iodine terminal of the polymer (p0-3) to —CH ₂ CH ₂ CH ₂ OCOCH═CH ₂ was 71%, and triethylamine hydrochloride was removed. Confirmed that it has been.

(Evaluation of photocurability and liquid repellency)
0.1 g of the polymer (p6-4) and 0.9 g of perfluorobenzene were placed in a 6 mL glass vial and sufficiently stirred to obtain a uniform solution. The obtained solution was filtered through a polytetrafluoroethylene filter having a pore size of 0.20 μm to prepare a resin composition. Photocurability and liquid repellency were evaluated using the resin composition.

Photocurability:
The resin composition was spin-coated on a slide glass (Matsunami Glass Co., Ltd., S9111) substrate at 1,000 rpm for 30 seconds, and heated at 100 ° C. for 120 seconds using a hot plate to form a dry coating film. . Using a high-pressure mercury lamp as a light source, exposure was performed for 2 minutes at an illuminance of 100 mW / cm ² under a nitrogen atmosphere.
When the dry coating film before exposure and the coating film after exposure were immersed in AK-225 (Asahi Glass Co., Ltd.) for 1 minute, the dry coating film before exposure was dissolved, whereas the coating film after exposure was dissolved. There wasn't. From this, it was confirmed that a cured film was obtained by exposure.

Liquid repellency:
The board | substrate with which the dry coating film before the said exposure was formed, and the board | substrate with which the coating film after exposure was formed were each immersed in AK-225. The dried coating film before exposure was dissolved in AK-225. Next, in each substrate, the contact angle of water in the portion where the coating film was formed or in the coating film was measured with a fully automatic contact angle meter (DM-701, manufactured by Kyowa Interface Science Co., Ltd.). The contact angle in the portion where the dried coating film before exposure was formed was 4 °, and the contact angle in the coating film on the substrate obtained by immersing the substrate on which the coating film after exposure was formed in AK-225 was It was 113 °.

  The fluoropolymer in the present invention has good crosslinkability because a crosslinkable group is introduced at the end of the molecular chain. The curable composition containing the fluoropolymer exhibits photocurability and can be finely patterned by adding a photoacid generator or a photopolymerization initiator as necessary. Useful as. Further, the cured product of the fluorine-containing polymer has a low dielectric constant, a low refractive index, and excellent transparency, water / oil repellency, heat resistance, gas permeability, and the like, so an electronic member (printed circuit board, etc.), an optical member (Optical waveguide, lens, antireflection film, etc.), water / oil repellency-imparting agent, release agent, biochip and the like.

Claims (12)

A monomer component containing a monomer having a fluorine atom and an iodine atom and a monomer having a fluorine atom and no iodine atom is polymerized to obtain a group represented by the following formula (g1) and the following formula (g2): A method for producing a fluorine-containing polymer having a crosslinkable group, wherein a precursor polymer having one or both of the groups represented is obtained, and an iodine atom in the following formula in the precursor polymer is converted to a group having a crosslinkable group .

However, R ¹ is a monovalent perfluoro organic group or a fluorine atom which may have an etheric oxygen atom, and R ² and R ³ are each independently a fluorine atom, a C 1-5 perfluoro An alkyl group or a perfluoroalkoxy group having 1 to 5 carbon atoms, and R ⁴ is a straight chain which may have a part of a 5-membered ring or a part of a 6-membered ring and may have an etheric oxygen atom Or it is a branched perfluoroalkylene group.   The monomer having a fluorine atom and not having an iodine atom includes one or both of a monomer having an aliphatic ring structure and a monomer capable of forming an aliphatic ring structure by cyclopolymerization. A method for producing a fluorine-containing polymer having a crosslinkable group as described in 1.   The method for producing a fluorinated polymer having a crosslinkable group according to claim 1 or 2, wherein the precursor polymer and the fluorinated polymer having a crosslinkable group are composed of branched molecular chains. The crosslinkable group is at least one selected from the group consisting of a group represented by the following formula (g3), an epoxy group, a vinyl group, and a group represented by the following formula (g4). The manufacturing method of the fluorine-containing polymer which has a crosslinkable group as described in any one of these.
-OCOCX ¹ = _CH 2 (g3)
-SiX ² _n (OR ⁵ ) _3-n (g4)
However, ^{X 1} is a hydrogen atom, a fluorine atom, a chlorine atom, a perfluoroalkyl group having 1 to 4 alkyl groups or carbon atoms having 1 to 4 carbon atoms, ^{X 2} is an alkyl group having 1 to 4 carbon atoms , N is an integer of 0 to 2, and R ⁵ is an alkyl group having 1 to 4 carbon atoms.   The manufacturing method of the fluoropolymer which has a crosslinkable group as described in any one of Claims 1-4 whose mass average molecular weights of the fluoropolymer which has the said crosslinkable group are 5,000-80,000.   A fluoropolymer having a crosslinkable group is obtained by the method for producing a fluoropolymer having a crosslinkable group according to any one of claims 1 to 5, and a curable composition containing the fluoropolymer is prepared. The manufacturing method of a curable composition.   A fluorine-containing polymer having a crosslinkable group, comprising a branched molecular chain having a unit having a fluorine atom, and having a crosslinkable group at a plurality of terminals of the branched molecular chain.   The fluorine-containing polymer having a crosslinkable group according to claim 7, wherein at least a part of the unit having a fluorine atom is a unit having a fluorine atom and an aliphatic ring structure. The fluorine-containing polymer having a crosslinkable group according to claim 7 or 8, which has one or both of a group represented by the following formula (g11) and a group represented by the following formula (g12).

However, R ¹ is a monovalent perfluoro organic group or a fluorine atom which may have an etheric oxygen atom, and R ² and R ³ are each independently a fluorine atom, a C 1-5 perfluoro An alkyl group or a perfluoroalkoxy group having 1 to 5 carbon atoms, and R ⁴ is a straight chain which may have a part of a 5-membered ring or a part of a 6-membered ring and may have an etheric oxygen atom Or it is a branched perfluoroalkylene group, and A is a group having a crosslinkable group. The crosslinkable group is at least one selected from the group consisting of a group represented by the following formula (g3), an epoxy group, a vinyl group, and a group represented by the following formula (g4). The fluorine-containing polymer which has a crosslinkable group as described in any one of these.
-OCOCX ¹ = _CH 2 (g3)
-SiX ² _n (OR ⁵ ) _3-n (g4)
However, ^{X 1} is a hydrogen atom, a fluorine atom, a chlorine atom, a perfluoroalkyl group having 1 to 4 alkyl groups or carbon atoms having 1 to 4 carbon atoms, ^{X 2} is an alkyl group having 1 to 4 carbon atoms , N is an integer of 0 to 2, and R ⁵ is an alkyl group having 1 to 4 carbon atoms.   The fluorine-containing polymer having a crosslinkable group according to any one of claims 7 to 10, having a mass average molecular weight of 5,000 to 80,000.   The curable composition containing the fluorine-containing polymer which has a crosslinkable group as described in any one of Claims 7-11.